Brass stretching

Discussions of powders, bullets and loading information.

Moderators: Kirk, Lucinda

Post Reply
User avatar
august west
Posts: 105
Joined: Wed Apr 29, 2020 7:32 am
Location: Ooltewah, TN

Brass stretching

Post by august west »

I'm planning a new order and am concerned about case availability for various options, naturally. I'm looking at 40-70 SS or BN, in a 26" Hunter's rifle style but go back and forth based on case availability. I'm really, really hesitant to use cases that are stretched from smaller brass, such as 45-70 cases stretched to 40-70 straight, or 44-90 stretched from 43 Spanish. Is this an irrational fear?

I don't want to resize cases, and I want to thumb seat PP bullets. Period. I also don't want to turn necks. My goal is healthy, thick brass that just has to be trimmed and sized down. As it stands from BACO now, the 40-70 BN is sized down, the SS is stretched from 45-70, which bugs me.

Also, is the expected case life of the lathe turned brass better than normal extruded brass? I've heard both ways.

Anyway, thanks for advice about stretched brass, whether it's an issue or not. I've split a lot of cases over the years but then I've always full-length resized like the handy/dandy RCBS instructions told me to do. I guess a case that is chamber dimension after firing, and is never resized, is never under any stress and should last indefinitely, just occasionally trimming for length?
"It ain't like it used to be but...it'll do." - Old Man Sykes
Perentie
Posts: 417
Joined: Mon Jul 21, 2014 9:22 am
Location: Queensland, Australia.

Re: Brass stretching

Post by Perentie »

I got Pacific Tool to grind a reamer to suit Hornady 405 Winchester brass. Full length as bought but with a .425 neck.
Once they are fireformed I dont need to do anything. Clean , load and hand seat my PP bullets.
TexasMac
Posts: 2364
Joined: Sun Nov 04, 2007 5:29 pm
Location: Central Texas
Contact:

Re: Brass stretching

Post by TexasMac »

august west wrote: Sun May 10, 2020 6:54 am I guess a case that is chamber dimension after firing, and is never resized, is never under any stress and should last indefinitely, just occasionally trimming for length?
I can't answer or comment on your other questions but will on the above. A fireformed case that is not resized is stressed during each firing, but not much. It will enlarge around 1 to 2 thousands than shrink back. If it did not extraction would be a problem. Although the main body of the case will last for many, many firings it will not last indefinitely as the primer pocket will slowly enlarge to a point that the case is no longer useful. As an example, I have 200 Rem. .40-65 cases that were reformed from .45-70. After firing about 8000 rounds (around 40 firings per case) with thumb seated bullets & 60 to 69gr loads the primer pockets on some were enlarging to the point that some of the cases were tossed.

Wayne
NRA Life (Benefactor & President's Council) Member, TSRA Life Member, NSSF Member, Author & Publisher of the Browning BPCR book
http://www.texas-mac.com
Gamerancher
Posts: 199
Joined: Mon Sep 19, 2016 4:29 pm
Location: Central NSW Australia

Re: Brass stretching

Post by Gamerancher »

I believe you've got your facts a bit muddled ol' mate. .40-70 straight cannot be made from .45-70 brass, wrong head size.
The stuff from Buffalo Arms is made from .30-40 Krag. I have been using it in my Shiloh for 8 years, some cases have been reloaded over 25 times each. I partiallly resize my brass every loading and trim for length when necessary. Loads used are from 60 to 70 grains of powder, firing 400 t0 440 grain bullets. I have lost maybe a dozen cases in all that time.
Out in western NSW where it don't rain much.
Australia
Clarence
Posts: 2167
Joined: Tue Dec 24, 2002 7:38 pm
Location: Hill Country, TX

Re: Brass stretching

Post by Clarence »

Wayne,

There is a shooter in Georgia that would disagree with you. I've seen him demonstrate removing primers by using his hand-seated bullets to apply hydraulic pressure, then reinstalling them by hand. He is always a serious contender... He obviously must store his ammo with primers up to avoid losing them.

Clarence
User avatar
august west
Posts: 105
Joined: Wed Apr 29, 2020 7:32 am
Location: Ooltewah, TN

Re: Brass stretching

Post by august west »

Thanks for the replies - I know "indefinitely" is silly - I was just using it as a figure of speech. What I was going for was what is the durability/life span of cases that are stretched out to form much larger cases. Apparently it's not a big deal and as long as you take good care of your cases and watch the primer pockets all is well.

It's my goal to stick with calibers, and cases, that don't have to be stretched out but can be formed from larger/longer brass, but even if I have to use stretched cases apparently it's not an issue.

And I misspoke - I was thinking of 40-70 BN - which is formed from 45-70 (or other 45 basic cases). I know 40-70 SS comes from 40 basic brass...brain lock. Stretching the 2.1" 45 case out to 2.25" was part of my original curiosity, along with stretching 43 Spanish to 44-90.

Thanks again.
"It ain't like it used to be but...it'll do." - Old Man Sykes
TexasMac
Posts: 2364
Joined: Sun Nov 04, 2007 5:29 pm
Location: Central Texas
Contact:

Re: Brass stretching

Post by TexasMac »

Clarence wrote: Sun May 10, 2020 5:10 pm Wayne,
There is a shooter in Georgia that would disagree with you. I've seen him demonstrate removing primers by using his hand-seated bullets to apply hydraulic pressure, then reinstalling them by hand. He is always a serious contender... He obviously must store his ammo with primers up to avoid losing them.
Clarence
Clarence,

I realize they will still work fine if real loose but I don't care to work with loose primers. Actually, more recently, I been using a pocket flaring technique with a ball bearing, flat end rod and an hammer to tighten up the pockets. So far it has worked great & significantly extends the life of the case. Here's a YouTube video on the technique: https://www.youtube.com/watch?v=1ST25CUpqhY&t=4s

Wayne
NRA Life (Benefactor & President's Council) Member, TSRA Life Member, NSSF Member, Author & Publisher of the Browning BPCR book
http://www.texas-mac.com
Kurt
Posts: 8428
Joined: Wed Oct 12, 2005 10:28 pm
Location: Not Far enough NW in Illinois

Re: Brass stretching

Post by Kurt »

If you don't want to stretch .45-70 cases for the .40 bn use .45-2.4 and trim them.
Unfortunately if you want .44-90 bn brass the .43 spanish is the only close brass you can still find unless for some custom brass you can still get for a price.
For the .40-70-2.5 There is another option and that is the 9.3X74R. I have used this case for my .40-2.5 but you need to turn or grind the round EZ edge on the bottom of the die to swage down about .01" of the base if your chamber is tight.
The reason a dog has so many friends is because he wags his tail instead of his tongue.

"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery"Winston Churchill
User avatar
august west
Posts: 105
Joined: Wed Apr 29, 2020 7:32 am
Location: Ooltewah, TN

Re: Brass stretching

Post by august west »

Kurt wrote: Sun May 10, 2020 6:52 pm If you don't want to stretch .45-70 cases for the .40 bn use .45-2.4 and trim them.
Unfortunately if you want .44-90 bn brass the .43 spanish is the only close brass you can still find unless for some custom brass you can still get for a price.
For the .40-70-2.5 There is another option and that is the 9.3X74R. I have used this case for my .40-2.5 but you need to turn or grind the round EZ edge on the bottom of the die to swage down about .01" of the base if your chamber is tight.
Thanks Kurt-

I'm hoping to use BACO's 44-90 brass which is made from 50-110.

Good point about 45-90. That settles that.

I'm going to stick with Shiloh's stock 40-70 BN chamber, so whatever works best for that.
"It ain't like it used to be but...it'll do." - Old Man Sykes
Kurt
Posts: 8428
Joined: Wed Oct 12, 2005 10:28 pm
Location: Not Far enough NW in Illinois

Re: Brass stretching

Post by Kurt »

august west wrote: Sun May 10, 2020 7:00 pm
Kurt wrote: Sun May 10, 2020 6:52 pm If you don't want to stretch .45-70 cases for the .40 bn use .45-2.4 and trim them.
Unfortunately if you want .44-90 bn brass the .43 spanish is the only close brass you can still find unless for some custom brass you can still get for a price.
For the .40-70-2.5 There is another option and that is the 9.3X74R. I have used this case for my .40-2.5 but you need to turn or grind the round EZ edge on the bottom of the die to swage down about .01" of the base if your chamber is tight.
Thanks Kurt-

I'm hoping to use BACO's 44-90 brass which is made from 50-110.

Good point about 45-90. That settles that.

I'm going to stick with Shiloh's stock 40-70 BN chamber, so whatever works best for that.

At this point with the unavailable brass I think the .40 bn is a good as any. Maybe the best.
A long time ago I had a roller in that caliber but it gave me fits o it went down the road for $50. :D
The reason a dog has so many friends is because he wags his tail instead of his tongue.

"Socialism is a philosophy of failure, the creed of ignorance, and the gospel of envy, its inherent virtue is the equal sharing of misery"Winston Churchill
mdeland
Posts: 11708
Joined: Mon Nov 20, 2006 1:47 pm

Re: Brass stretching

Post by mdeland »

Were are you getting 43 Spanish cases now to make anything out of? I need just that case and recently had to make them out of .348 brass which is a pain in the Keester!
Woody
Posts: 6060
Joined: Sat Feb 07, 2009 9:02 am
Location: Freetown, Indiana

Re: Brass stretching

Post by Woody »

I'm confused why any of you are getting loose primer pockets. I too watched "The Gaze" pump his primers, then shoot them. I've got some cases that have been fired with frequency for twenty years plus. I have never experienced a loose pocket in a black powder case. I suspect that you are causing them by aggressive scraping during your cleaning routine.

I am slowly losing one or two percent of my cases on each firing now. They split longitudinally in the neck. I neck size only and don't anneal. These are Winchester brass in both 45-70 and 40-65 that have an untold number of cycles through the rifle.

My 45-90 Starline brass is a different story. They are annealed and require constant attention to length, as they do stretch upon firing. Their primer pockets have remained stable and have not loosened.

Woody
Richard A. Wood
If you are surrounded. You are in a target rich environment.
Woody
Posts: 6060
Joined: Sat Feb 07, 2009 9:02 am
Location: Freetown, Indiana

Re: Brass stretching

Post by Woody »

I'm confused why any of you are getting loose primer pockets. I too watched "The Gaze" pump his primers, then shoot them. I've got some cases that have been fired with frequency for twenty years plus. I have never experienced a loose pocket in a black powder case. I suspect that you are causing them by aggressive scraping during your cleaning routine.

I am slowly losing one or two percent of my cases on each firing now. They split longitudinally in the neck. I neck size only and don't anneal. These are Winchester brass in both 45-70 and 40-65 that have an untold number of cycles through the rifle.

My 45-90 Starline brass is a different story. They are annealed and require constant attention to length, as they do stretch upon firing. Their primer pockets have remained stable and have not loosened.

Woody
Richard A. Wood
If you are surrounded. You are in a target rich environment.
User avatar
august west
Posts: 105
Joined: Wed Apr 29, 2020 7:32 am
Location: Ooltewah, TN

Re: Brass stretching

Post by august west »

mdeland wrote: Sun May 10, 2020 9:55 pm Were are you getting 43 Spanish cases now to make anything out of? I need just that case and recently had to make them out of .348 brass which is a pain in the Keester!
Dixie Gun Works supposedly has them. Website lists them in stock.
"It ain't like it used to be but...it'll do." - Old Man Sykes
Clarence
Posts: 2167
Joined: Tue Dec 24, 2002 7:38 pm
Location: Hill Country, TX

Re: Brass stretching

Post by Clarence »

Woody,

My experience largely mirrors yours. have some WW .45-70 brass I bought in the mid-80's-it had the cannelure. It was fired at least 30 times in the .45-70, and then formed to .40-65 and has been fired 6-8 times more. The primer pockets are not nearly as tight as the Starline brass, but the primers don't fall out.

I don't scrape primer pockets, but I do anneal-so far, the only case loss is from crushing the case mouth when I don't pay attention while using the expander die, and a few from not making sure the case mouth is perfectly round before reforming.

Clarence
Post Reply